[protector] Bump Preferences backup version to 3 to mitigate the startup prefs migration.

chrome/browser/protector/protector_service.cc

 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "chrome/browser/protector/protector_service.h"
 
 #include "base/logging.h"
 #include "chrome/browser/google/google_util.h"
 #include "chrome/browser/prefs/pref_service.h"
 #include "chrome/browser/protector/composite_settings_change.h"
@@ skipping 101 matching lines @@
 
 void ProtectorService::OpenTab(const GURL& url, Browser* browser) {
   DCHECK(browser);
   browser->ShowSingletonTab(url);
 }
 
 ProtectedPrefsWatcher* ProtectorService::GetPrefsWatcher() {
   return prefs_watcher_.get();
 }
 
+void ProtectorService::StopWatchingPrefsForTesting() {
+  prefs_watcher_.reset();
+}
+
 ProtectorService::Item* ProtectorService::FindItemToMergeWith(
     const BaseSettingChange* change) {
   if (!change->CanBeMerged())
     return NULL;
   GURL url = change->GetNewSettingURL();
   for (Items::iterator item = items_.begin(); item != items_.end(); item++) {
     if (item->change->CanBeMerged() &&
         CanMerge(url, item->change->GetNewSettingURL()))
       return &*item;
   }
@@ skipping 80 matching lines @@
 ProtectorService::MatchItemByError::MatchItemByError(
     const SettingsChangeGlobalError* other) : other_(other) {
 }
 
 bool ProtectorService::MatchItemByError::operator()(
     const ProtectorService::Item& item) {
   return other_ == item.error.get();
 }
 
 }  // namespace protector